For atherosclerosis of coronary arteries and peripheral blood vessels, therapy by surgical replacement or bypass surgery is performed. For affected parts with a diameter of 5 mm or less, an autologous blood vessel is a preferable graft for replacement wherein the most frequently used grafts are autologous internal mammary artery, radial artery and saphenous vein, which are known to have a good patency rate. However, there are problems such as unavoidable invasion for obtaining a graft, variability of its length or quality depending on each case, and unavailability of a graft in reoperation cases where a graft has already been used.
On the other hand, an artificial blood vessel such as Dacron and ePTFE has been used for revascularization of peripheral arteries of limbs but cannot be used in blood vessels with a small diameter such as coronary arteries due to early formation of thrombus and hypertrophy of the tunica intima. In recent years, it has become possible to coat the lumen of an artificial blood vessel with vascular endothelial cells by seeding the cells within the artificial blood vessel with a tissue engineering technique to thereby prevent blood coagulation. However, before surgery, the bone marrow must be taken from patients, cultivated and engrafted to an artificial blood vessel, which takes time and is costly. In particular, in cases of urgency such as coronary artery bypass, its utility is low.